Solution:

1.There are two IDE device need to set to “Master” mode on hard disk side. 2. a.) If you plug a HDD to lower drive, then power on the system. It will show “ACCUSYS ACS7500 CDVL ACCUSYS” on Primary Master during POST. b.) If you only plug a HDD to upper drive, then power on the system. There is nothing to show on Primary channel during POST, so you cannot boot into OS. (Now, this is a limitation issue) 3. Now, you have to plug a HDD to lower drive, lock up and power on the system. Then plug secondary HDD to upper drive and lock up. The RHC-IDE-2R will make RAID 1 automatically. 4. After RAID1 is finished. The system will boot into OS smoothly and you can remove lower or upper drive when one of HDDs is defective. For example; If your lower HDD is defective on; A. Power on and boot into under OS.) You can take a new HDD to replace lower defective HDD immediately. After then the RHC-IDE-2R will make RAID 1 automatically. B. Turn off the system.) You must take a new HDD to replace lower defective HDD. Otherwise, the system cannot boot into OS. The RHC-IDE-2R will make RAID 1 automatically and boot into OS after you insert a new HDD to lower drive.